Vacuum device



Sept. 13, 1932` w. J. WEST VACUUM DEVICE Filed oct. 9, 1928 lllllllllllllllllllllllllll l.

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Patented Sept. 13, 1932 UTE STATES PATENT foFFlcE WALTER J'. WEST, OF CLEVELAND, OHIO, ASSIGNOR TO LUCIAN` TUBE CORPORATION,

OF CLEVELAND, OHIO, A. CORPORATION OF OHIO VACUUM Y DEVICE Application filed October 9,1928. Serial No. 311,264,

This invention relates in general to vacuum devices such as audions employed in radio circuits7 broadcasting tubes as employed in the operation of radio broadcasting stations, and rectifier tubes.

One of the objects orp this invention is the provision of a novel form of structure in vacuum devices which is relatively simple in production and adapted for rapid and cheap manufacture.

A further object of this invention is the construction of vacuum devicesemploying cathodes and independent heating elements therefor which heatingelements are easily removable for replacement.

A still further object of this invention con templates a vacuum device employing the usual and standard base construction having a detachable element for removably supporting the heater element.

Another object of this invention is to provide a vacuum device having a heating element in which all the terminals of the device issue from one end thereof.

Another object of this invention contemplates a construction in which the cathode is a hollow tube passing through the stem tube orp the bulb externally of the base so that the heater element may be placed therein.

These and other objects as will appear from the following disclosure are secured by means of this invention.

This invention resides substantially in the combination, construction, arrangement and relative location of parts all as will appear more fully hereinafter.

Figure 1 is a vertical cross-sectional View through the device of this invention with the section taken so that the prongs on the base are shown in actual position.

Fig. 2 is an enlarged sectional view of the cathode heater ports for the grid.

F ig. 3 is a cross-sectional view taken on the line 3 3 of Figure 2.

Fig. 4 is a plan View of the electrode assembly of the device.

Fig. 5 is a plan view of the removable member of which the heater element is attached.

vto one of the grid and plate and the sup- In the construction vof tubes for use in radio circuits, especially the types employing heater elements, it is desirable to provide a structure in `which the heater element/is removable from the device so that it may be replaced when itis worn out. 1 The device of this invention employs a hollow cathode tube extending to the exterior of the Vdevice so that the heater element'may be slid into and out of the hollow tube. An additional feature of the present device is a removable plate or disc to which the heater element and the contact prongs therefor are attached. By means of this structurea practical and relativelyv simple arrangement is provided by means of which these objects are secured. Referring to the drawing the device is shown comprising an evacuated vessel 1 having a re-entrant stem 3. The usual insulating base 2 is provided for the vessel and is cemented thereto in the usual manner. Supporting up the stem tube members are the rods 4 which serve to support the cylindrical plate 6 by means of the conducting elements V5. Similarly supported in the stem tube mem- *a bers are the rods 7 which extend upwardly outside of the plate element and cooperate with the conducting elements 84which extend Within the plate element to support the grid 9. Extending through the stem tubev and So forming an airtight seal therewith Vis a conducting tube 10 which extends inside of the tube centrally of the grid and platestructures and which extends outside of the tube through the base 2 as clearly shown in Figure 2. Secured to the base 2 are the contact prongs 11, 12 and 13. Prong 11 is connected by wire 16 plate supports 4.-. Prong 12 is connected by wire 17 to one of the grid supports '7. Prong 13 is connected by wire 18 to the cathode 10.

An insulating disc or plate 19 is provided with th-e holes 22, 21 and 23 through which prongs 13, 12 and llrespectively pass when the disc is in place as shown in Figure 1. Secured to the disc 19 are two additional contact prongs 14 and 15 to which are connected the two ends of the heater wire 40. The heater wire is embedded in any suitable insulating material and is of such size and shape as will 'without departing permit it to pass into the interior of the cathode tube 10 as clearly set forth in Figure 2.

As is usual in these structures the conducting tube 10 is coated on the surface which lies within the Volume deined by the plate with any suitable electron emissive substance. By the structure described the heater element is supported solely upon the disc 19 and is electrically connected by the two prongs thereof. When the disc 19 is slipped into place as shown in Figure 1 the result is a tube having a standard base with live prongs. VIt might be pointed out here that if desired this arrangement is adapted to a construction involving the use of a greater or lesser number than five prongs and that in the case of a four prong construction the negative ilament lead would be connected to prong 13 to which the cathode is connected, thereby eliminating either prong 14 or 15.

By means of this arrangement it will be at once apparent that the heater element should it become worn out may be replaced by simply sliding disc 19 from prongs 13, 12 and 11 and withdrawing the heater element from the cathode tube. Thus when the destructed part of the device needs replacement this can easily be accomplished without requiring the other parts thereof to be discarded.

It is at once apparent that the device of this invention embodies certain principles which may be embodied in numerous practical forms from the scope of the invention and it is desired, therefore, that the ield of the invention be not restricted by the disclosure only but shall be as broad as may be consistent with the full legal eiiect of the appended claims as well.

Vhat I desire to claimby United States Letters Patent is:

In a device of the type described, the combination comprising an evacuated vessel, a base secured to said vessel having a plurality of contact prongs thereon, a plurality of elec trodes supported within said vessel each connected to one of said prongs, one of said electrodes being a hollow tube extending eXteriorly of the vessel, a removable member hav- Ving prongs thereon and openings to fit over the prongs of the base, and a heater element attached to said removable member and adapted to be inserted within said hollow tube, said heater element being connected to the prongs on said removable member.

In testimony whereof I have hereunto set my hand on this 26th day of September A. D.,

WALTER J. VEST. 

